Four of clubs = "Devil's Bedpost"?

I've really no idea about this one. The
Oxford English Dictionary gives the following
citations:

1873, John C. Hotten, A dictionary of modern
slang, cant, and vulgar words: Devil's
bed posts, the four of clubs.
1879, Notes & Queries, 5th Series. XII, 473:
I have always heard the four of clubs called the
devil's bed-post, and also that it is the worst
turn-up one could have.

Eva Beate B-J suggests that it may be linked to
Cartomancy (reading ordinary playing-cards instead of using
Tarot cards) and the Personal Prophesy method, where the 4 of Clubs
signifies misfortune, "the devil's bedpost". This card warns
of a major setback, an unexpected set of circumstances that must be
prepared for. It is also said that this card can be thought of as
"Murphy's Law" when used in readings.

On the other hand, this
unfortunate connotation could have been transferred from
a card game into cartomancy. Please
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